The objective of this work is to better identify tissue culture conditions which will allow successful allogeneic transplantation of fetal mouse pancreases into a diabetic mouse of another strain (i.e., without rejection of the fetal pancreas and with resultant cure of the diabetes). The methods will consist of: 1.) Tissue culture of donor fetal mouse pancreases under varying conditions, followed by histochemical staining of the pancreases to evaluate viability of the islets. 2.) When the islets in 1) still appear viable, syngeneic and allogeneic transplants will be done using donor pancreases incubated in tissue culture conditions similar to 1). Recipient mice will be 3 months old males made diabetic using streptozotocin. Following transplantation they will be followed for: weight gain, blood and urine glucose levels, and mean and medial survival times. 3.) Dr. Talmage will continue to do studies as in 2) above except donor adult thyroid glands are incubated in tissue culture under varying conditions and are then transplanted into recipient adult hypothyroid mice. He previously showed allogeneic transplantation of thyroid glands possible following tissue culture of the donor pancreases in high oxygen, high temperature and high pressure. Results of thyroid studies are quickly available and continue to give suggestions for alterations in tissue culture which might be useful for the pancreas studies. It is to be emphasized that the ideal conditions for tissue culture of the pancreas to negate allogeneic pancreas transplant rejection are still unknown; if they were known, people with diabetes would now be able to be cured. Secondly, others are not working with tissue culture of fetal pancreas, and are not using the whole pancreas.